Method and apparatus for making shell-forgings



' AI". A. SHERMAN AND I. M. HALL.

METHOD AND APPARATUS FOR MAKING SHELL FORGINGS.

APPLICATION FILED AUG.2| 1918.

1,347,415. Patentedghl 20,1920.

2 S S-SHEET l.

F. A. SHERMAN ANDI. M. HALL.

METHOD AND APPARATUS FOR MAKING SHELL FORGINGS.

APPLICATION FILED AUG.2. 1918.

DUH

mm w

NFD

my QN UNITED STATES PATENT OFFICE.

FRANK A. SHERMAN AND JOSEPH M. HALL, 0F HAMILTON, ON TARIO, CANADA.

METHOD AND APPARATUS FOR MAKING SHELL-FORGINGS.

Specification of Letters Patent.

Patented July 20,1920.

Application led August 2, 1918. Serial No. 247,957.

T0.aZl whom it may concern.'

Be it known that we, FRANK A. SHERMAN and JOSEPH M. HALL, citizens of the United States, and residents of Hamilton, in the county of Wentworth, Province of Ontario, and Dominion of Canada, have invented new and useful Improvements in Methods and Apparatus for Making Shell-Forgings, of which the following is a specification.

This invention relates to a method and apparatus for making metal shell forgings such as are employed in projectiles, although the same may also be employed to advantage in producing other hollow, tubular or cupshaped forgings for other purposes.

In the manufacture of such forgings, as heretofore practised, the die which receives the billet or blank was usually held stationary so that when this blank was subjected to .the endwise pressure of the mandrel or piercingpin, the metal of the blank would flow lengthwise of the bore of the die which not only required a great deal morepower to produce the hollow forging but also would wear the bore of the dieunduly rapid so that frequent relining of the same was necessary and therefore increased the cost of production.

One of the objects of this invention is the provision of a method and apparatus for making shell forgings or similar tubular or cup-shaped articles in which the blank while subjected to endwise pressure for forming the cavity therein is restrained against lat eral movement but is free to move lengthwise without appreciable friction of its outer side against the bore of the die, and -thereby facilitate the formation of the forging as well as eliminating the excessive wear on the die.

Other objects of this invention are to provide simple means for keeping the die cool,

to provide efficient means for guiding the mandrel, punch or piercingv pin during its working stroke and also stripping the finishing forging therefrom after the latter is completed, to provide means for ejecting the finished blank, and to improve the apparatus in other respects for increasing the efficiency of the same, simplifying its construction and reducing its cost of manufacture.

In the accompanying drawings: Figure l is a vertical longitudinal section of a practical embodiment of an apparatus for practising our invention taken on line l-1,

Fig. 5, and showing the position of the parts when beginning a forging operation. Fig. 2 is a fragmentary vertical longitudinal section on the same line, showing the position of the parts when a forging is completed. Fig. 3 is a fragmentary vertical section taken on line 3-3, Fig. 5. Fig. 4 is a top plan view of the apparatus. Fig. 5 is a horizontal section taken on line 5 5, Fig. l. Fig. 6 is a fragmentary vertical section showing a modified form of the means for ejecting the finished forging. Fig. 7 is a sectional perspective view of the outer tubular body of the die pot showing the manner of constructing the water cooling passage therein.

Similar characters of reference indicate corresponding parts throughout the several views.

In its general organization, the apparatus for practising our invention comprises a die having the form of a pot which is adapted to receive the blank or billet l which is to be forged into tubular or cup-shaped form, and .a mandrel, punch, plunger or piercingpin which engages the blank endwise. The die pot has a tubular wall and a bottom arranged within one end of the same while the opposite end of this wall is open to form a mouth through which the blank is inserted into and removed from the die as the mandrel enters and leaves the same. In the preferred construction of the wall of the die pot, the same comprises an outer tubular section or body 2 and a tubular lining or inner section 3 arranged within this outer section and capable of being removed therefrom so that when this lining becomes worn the same can be renewed. The bottom of the die pot preferably comprises an outer or lower body-section 4: and an upper or inner wearing section 5 which is seated on the inner end of the bottom body section and is capable of being reversed so that its opposite sides can be used successively until worn out and then replaced by another inner section.

The bottomof the die pot has its lower or outer section preferably mounted rigidly on a base which is secured to the lower stationary platen of a hydraulic or similar press, this base in its preferred form comprising a central body portion 6 which is provided at its lower end with a laterally-projecting flange 7 whereby the same is connected with the lower platen of the press While its upper end is provided with an annular recess S in whichI any attaching flange 9V Vat the lower end of the bottom body is seated and secured'therein by means ofv bolts 10, as shown in Fig. 3, or by other suitableV means. Adjacent to the recessin theV body of the base, the same is provided. on` its upper 'side Vwith anl annular upwardly-` facing shoulder 11 whichV is engaged by the lower end of the tubular body or o'uter section of the diepot wall and limits the downv` `ward movement'of the latter. Outside of Y this shoulder the base is provided with an upwardly-'projecting tubular guide or sleeve 12 which engages with the lower .periphery of the wall-body and serves together withV the lower section of the bottom as a guide forthe die pot ina direction lengthwise of itsfaXis. I

In order to prevent bore of theV die pot lining and the periphery of the die bottom from interfering with the downward movement 'of the die pot in its lowermost position, the lower end of the dieV pot wall is provided with an annular recess 13 into which any such material is directed and gathered, thereby avoiding the objectionable effects just mentionedj For the same purpose an annular pocket or recess 14 is f formed in the bore of the guide tube or sleeve 12 between its upper and lower edges, so

Vthat any dirt which may work downwardly through the joint between this guide sleeve and the guide pot wall will be collected in :this pocket and prevented from reaching the space between the shoulder of the base and the lower end of the die pot body which otherwise'` would prevent the latter from moving downwardly into its loweiniost position and seat itself properly on the base.

rlfheentrance of any foreign matter, suoli as dirtand dust, between the die pot wall and the guide sleeve is however prevented or atleast minimized as much as possible by the employment of a packing 15 which is Y arranged in an annular undercut rabbet or groove 16l inthe upper edge of the guide sleeve and engaging with the periphery of the body of the die pot wall, and also by Y providing this body immediately above this packing with. a laterally-projecting guard I flange 17 which overhangs the upper end ofV .the guide sleeve and the packing therein Y clined surface 18 so as to shed any foreign and is provided with an upper outwardly-inmatterlaterally beyond the. periphery of the guide sleeve and keepthe same .from en tering lthe. joint between the die pot wall and the guide sleeve.

Preparatory to forging la billet or blank between'the die andfmandrel, the same is heated to awhigh temperature, usually about tvv'ofthousand degrees Fahrenheit, and it is Y therefore desirable to provide means forV part of the any scale or dirt Vwhich may work downwardly'between the cooling the die pot'so las to prevent the same from being affectedinjuriouslyr T heineans Y suitable for this purpose which are shown in the drawings,'particularly in Fig. 7', com- 'prise a plurality of annular lgrooves. 19

formed in the bore of the diepot body-,a plurality ofglongitudinal connecting grooves 2O which are arranged in staggered-relation to each other on opposite sides ofthe bere Vof the die pot body and each of which connects the corresponding ,parts of two' adjacent annular grooves, an angular inlet v"passage 21leading from the lowermost annuto be connected with a supplyrofcooling lar passage 21 and providedxwitha lateral Ylnletbranch passage V23which is adapted medium such as water, andan outlet branch passage '24 Vextending A uppermost annular groove and adapted to' be connected withal waste pipe or line infany suitable manner. The water for cooling'the die pot entering thesupply branch V23 passes thence successively through the annular passage 22, the angularpassage 21, the several annular andflllongitudinal' grooves 19, 2G, and then escapes through the outletrpass'age 211, thereby reducing the temperature of the die potrand maintaining the same ina condition'bestsuited for working the metal of' the billetV and prolonging'the life of 'the' laterally' fromV the.,

apparatus. 'inasmuch as the angularrsupi ply passageV 21 opens intol the lower end Y of theV die Apot body and the space witliin the llatter ConnectsV with theinlet 23 the wall:

of the die pot-'is Vfree to rise andV fall Vwitlioutfdisturbing the water connectionfwith the source of supply.` Y Y. Y Y

Above the wall of the diepottlie sameV is outer part of its'lower or inner end against the 'upper end of the die potbody while its innerV portion is provided withAV a down V,wardly#facing shoulder Y 27 nwhich engages theV upper end ofthe die potvlining, but the bore 'of this capv is larger than Vthe* bore of the lining, as clearly'shownin-rFig. 1., This pot wall are detachably connected with each otherin order -to permitthe renewal ofthe lining when necessary, this connection as shown in the drawings, consisting'preferably of a plurality ofy upright coupling bolts or rods 28 each of which passes through a corresponding pairrof coupling lugs 29, 30, on:` the outer side-off the lcap and the die provided with atubular 25'which has a Vcentral opening'26 for the passageof the forming mandrel.' This cap bearswith the -cap and the outerpsectionor body of the die'V Apot body and Vprovided Ywith an upper screw Y.

nut 31 engaging'with the upper'side of the coupling lug ofthe cap and a lowei` screw nut 32 engaging with the underside of the coupling lug of the die pot body.'

The upward movement of the die pot and associated parts during the operation of forging a shell or similar tubular or cup-shaped article is preferably so timed that this movement ceases before the lower end of the die pot wall reaches the upper surface of the die pot bottom during which time the upward movement of the die pot is unrestrained. After the forging operation has been completed the finished forging is moved upwardly out of the die pot but in order to limit the upward movement of the die pot at this time and permit the iinished forging to be removed therefrom, a stop device is provided which preferably comprises a php rality of iifurcated or notched stop lugs arranged on vhe outer side of the guide sleeve and each receiving the lower end of one of the coupling bolts 28, the lower end of this bolt being provided with a crosshead 311 forming an upwardly-facing shoulder which is adapted to engage with the underside of the respective stop lugs 38. As the die pot rises during the operation of the forging blank the heads Se of the several coupling bolts move idly upwardly toward the underside of the stop lugs and at the end of the 'movement of the die pot the same stop short of engaging the stop lugs 33, so

that they do not exert any upward pressure against these lugs, otherwise there would be danger of either breaking these bolts or lugs owing to the enormous pressure under which the die pot is moved upwardly during the forging operation. lVhen, however, thereafter the finished vforging is ejected forwardly from the die pot by a comparatively low upward pressure against .this forging, the heads of the several coupling bolts by engagingwith the undersides of the stop lugs serve to arrest the further forward movement of the die pot and cause the forging to be ejected from the die pot.

The mandrel which forms the cavity withing the hollow forging is preferably provided with a downwardly-tapering lowerl end or nose 35 and an upper cylindr ,al body 36 and the same is mounted at its upper end on the upper vertically inereplaten of the press so that this mandrel is arranged axially in line with the die pot.

In order to insure perfect concentricitrT of Y the mandrel relative-ly to the die pot when these parte cooperate for producing` a. cup shaped forging from a solid blank, a centering or guiding device is provided which preferably is constructed in the form of a ring 3'? the lower part 38 of its peripheral su face being preferably made of downwai ly-tapering form and adapted to engage with correspondingly inwardly-taperi face 39 in the upper part of the bore of thedie pot cap, As the mandrel ing operation has been completed, the mandrel is withdrawn so that the same is arranged above the die pot and associated parts a sufficient distance to permit the removal of the centering ring from the die cap and the forging from the die pot. In order to permit of readily applying the centering ring to the die cap and the removal therefrom as well as preventing this ring frombeing carried upwardly to an undue extent by frictional contact with the mandrel, the upper end of the die pot cap is provided on diametrically opposite sides with two stop hooks 40, l0 having their upper ends overhanging inwardly and providing the centering ring on its diametrically opposite sides with two stop lugs 1li, il which play vertically in the spaces be' tween the upper end of the die pot cap and the overhanging portions of the stop hooks. These spaces are sufficiently high so as to permit the centering rinov to be moved laterally over the die pot cap and then dropped with its conical or tapering portion into engagement with the corresponding face of the die cap as well as the removal of the same in like manner. YV hen, however, the mancrel is raised after a forging operation 1GO and the forging has a tendency to stick thereto, this centering ring is raised by such forging until the stop lugs of the centering 1. engage with the over-hanging upper ends of the stop hooks, thereby arresting 195 the further upward movement of the centering ring and causing the finished forging to be stripped from the mandrel during the continued upward movement of the latterY This centering ring therefore operates both 110 as a centering guide for the mandrel and also as a stripper for removing the finished forging therefrom.

For the purpose of quickly and effectively removing the finished forging from the die 115 pot, an ejecting device is provided which may be variously constructed, but which shown in Fig. l is constructed as follows:

e2 represents a main or outer power cylinder arranged vertically in the base and 120 adapted to be supplice at its lower end with a p 1essere medium such as water pressure by means of a supply passage communi eating with the lower end of the cylinder and adapted to be connected with a water 126 supply under pressure. Sliding vertically within this cylinder a main or outer piston le w i'jh is adapted to be raised by the admission of the pressure medium into the pressure cylinder. Eatending upwardly 130 Vfrom thispiston. and through corresponding openings 45, i6 in the lower and upper sections ofthe diebottom is the outer or main :passage 4:8 in the main section Llof an ejector rod. The main ej ector rod section is made hollow to form an innerfor auxiliary power cylinder which communicates with the main cylinder by a piston. Within the auxiliary power vcylinder is arranged an inner or auxiliary piston i9 which has con- .'nectedtherewith an inner ejector rod section 50 extending through the upper end of the outer ejector rod section.

j movement of the auxiliary piston is limited Vbythe lower endl of the hollow ejector rody i ,20 vand. its upward movement is limited by an' y formed at. the upper end .ton .rod section.

f the centering Y .from the die cap. the samediameter as the bore Vof the die pot same extends preferably up ,to a line located belowthe y The downward `movement of the main piston, is limitedV by the bottom of vthe main cylinder ,and its upward inovementby the top ofithis VVcylinder, and the vdownward internal downwardly-facing shoulder 5l of thehollow pisn' the. operationof this apparatus the blank 1 tobeforged is introducedintothe die pot while the 'wall thereof is in itslowered position and the mandrel elevated and 'This blank is Vnearly of lining so asto.` fit loosely therein and the from the bottomthereof and upper end of the lining, for instance the line 52 shown in Y Fig. l. The centering guide r and stripper ringis now applied to the up- Y per end of the die cap and then the plunger lormandrel is lowered so that it passes dow-nwardly through the guide and stripper ring Vand exerts endwise pressure Vagainst the blank from thez .upper toward the lower end Vthereof until the parts assume the position indicated in Fig. 2. During the initial portion of the downward movement of the inandrel in engagement with .the blank, the latter is iirst .spread until it completely fills the Y lower part of thediepot and firmly engages its bottom and lining. As the mandrel continues its downward movement in the blankl and forms a pocket or cavity 53 therein, the metal ofthe blank displacedV by such movement of the mandrel is caused to move upwardly orlengthwise in the form of a tuvbular .wallt through the Space between Vthe mandrel and'the bore of the lining in a di- Y iection opposite to the movement ofthe ,mandrel- Owing to the tapering form of the nose or lower end of the mandrel, the

-metal blank ismoved laterally by the wedge vaction of thenose against the bore of the lining vand lproduces a very powerful fric-V tionalcontact between the blank and the lining,so.that as the displaced metal moves l upwardly-between the mandrel and the die -pot wall,.tliel latter is carried upwardly with drel, the. la

guide stripping ring removed andremoved from the apparatus.

- outer 'piston and the metal of the blank until the forging Yoplower. end of the die' pot wall has nearly eration has been completed by the time the Y reached the top on'the die pot bottom.V

After the metal has been displaced laterally bythe lowertapering portion of the mandrel andzhas moved upwardly beyond this tapering port'of the same, it continues itsy upward movement between the cylindrical part of the mandrel and the adjacent cylindrical bore of the die potlining under reduced frictionaleonta'ct between they tubu-Y lar wall 54er the blank and the cylindrical:

part of themandreland the upper part of the Vdie pot lining, so that thejfriction'al resistance tothe upward Vtively free. Y Y A j Y Y After the forging operation has been thus completed, the upper platen of the press is raised together with the mandrel, so that the latter is clear of the guide and stripper ring,

' andV if during Vthis movement the finished blank has a VItendency to adhere to the Vmantenwill be stripped from the 550V a movement Vof thev metal of the blank' at this time is comparamandrel Vand y caused te remain Ywithin ftheV 1 die pot by engagement of the upper'endof the finished' forging withthe underside of the guide and stripperring, whiclrlatter at this time is heldy against continued upward movement by engagement with the step hooks ofthe die cap.' rlfhereafter the operator removes theV centering Vand stripper ring and then admits water pressureinto the lower end of'. the main power cylinder, so that the ejector rod sections by engagingwith the lower end of the finished mit the saine to bereached by a pair of tongs Y When' admitting water pressure first .raised and its hollow rod section is lifted together with the forging ,engaged therewith until the Vouter piston engages with the topof the mainv cylinder. Thereafter the continually entering pressuremediuininto theouter cylinder passes hrough tliepassage in the into'l the lower end of the ejector rod,` after is raised and itslinner ejector hollow outer inner piston .rod section by engaging with; the finished forging continues the upward lift of the latter until the inner pistonengages with theV inner surface oftherupper bottom section to theV lower end of the outer power or main cylinder after a forging operation has been com-Y ypleted, the outer piston is which the f Yof its stop lugs i ioo foi-ging lift the same sufficiently high to perv forming a pocket therein, so that when the blank is forged into shape a boss 55 is formed centrally on the head 56 which closes the lower endfthereof which boss is subsequently used for centering the forging in a lathe during the operations of finishing the same into a shell or projectile.

Instead of constructing the ejector rod in the form of telescopic sections, as shown in Fig. l, the same may be constructed of a single section 57 which is connected with a single piston 58 in the power cylinder 42, as shown in Fig. 6.

By thus mounting the wall of the die pot so that the same moves with the flow of the metal which is being forged, the power rey quired to operate the press is materially reduced and the wear upon the bore of the die pot is minimized, so that the cost of maintaining the apparatus in perfect working condition is materially reduced.

Furthermore, by employing the centering ring which maintains the mandrel concentric with the die pot, it insures the formation of a Acup-shaped or shell forging in which the wall is of uniform thickness in all parts of its circumference, and it also permits of producing such forgings regardless of whether the ends of the blank when placed in the die pot are uneven by reason of irregularities in the fracture, cuts or breaks in the same when these blanks or billets are formed in sections from a long stock bar of this material.

As the nose of the mandrel enters the metal of the blank that portion of the metal between this nose and the bottom of the die pot is worked on the surface of the billet or blank, so that the metal in the forging is of more uniform consistency and any pores which Vmay be present in the blank are removed therefrom.

Moreover, by allowing the wall of the die pot to rise, the steel or metal is caused to flow generally in the same direction in which this occurs when forming forgings ofV this character by forcing the same through a drawing ring, as has been heretofore practised, so that the present 'method and apparatus retains all of the advantages inherent in the methods heretofore known with the added advantages derived from the improvements forming the subiect of this invention. l This apparatus for practising our invention can be Vproduced at considerably less cost than that required heretofore for this purpose, the forgings can be produced quicker'and atless cost; the original cost of equipment is reduced; a sma ler press will sufce to operate the movable parts and owing to the reduced pressure which is required, the wear upon the mandrel is reduced and less frequent renewal of the same is necessary.

lll e claim as our invention:

l. An apparatus for making shell forgings comprising a die pot having a tubular wall and a bottom arranged at one end of said wall, said wall being movable lengthwise relatively to said bottom, a mandrel adapted to enter the opposite end of said tubular wall, a base having a central body which carries said bottom and is engaged by the adjacent end of said wall and tubular guide arranged on said body and engaging slidingly with the outer side of said wall, a pacl ing interposed between said guide and wall, and a defiecting flange arrangedpon the outer side of said wall and overhanging the end of said guide.

2. An apparatus for making shell forgings comprising a die pot having a longitudinally movable tubular wall, a bottom projecting into one end of said wall and having a flange at its outer end, a mandrel movable lengthwise into said wall through the opposite end thereof, and a base having a central body which is provided at its top with a recess in which the flange end of said bottom is secured, a shoulder around said recess which is engaged by the inner end of said wall, and a tubular guide arranged outside of said shoulder and engaging slidingly with the outer side of said wall.

3. An apparatus for making shell forgings comprising a die pot having a longitudinally movable tubular wall composed of a tubular body and a tubular lining engaging the bore of said wall, a bottom engaging with the inner end of said lining and a tubular cap engaging with the outer ends of said wall and lining, a longitudinall movable mandrel adapted to pass througii said cap and enter the adjacent end of said lining, and means for limiting the movement of said pot wall away from the bottom thereof comprising coupling lugs arranged on said pot body and cap, a base carrying said bottom and provided with stop lugs, and bolts each connected with a corresponding pair of coupling lugs on said pot body and cap and provided with a head adapted to engage its upper side with the underside of one of said stop lugs on the base.

ll. An apparatus for making shell forgings comprising a die pot having a tubular wall, a bottom arranged within the inner end of the wall and a tubular cap arranged on the outer end of the wall and having an inwardly tapering seat at the outer end of its bore and two inwardly overhanging stop hooks arranged on diametrically opposite sides of the outer end of the cap, a

longitudinally movable mandrel adapted to enter said die pot from the outer end thereof, and a guide and stripper ring adapted to engage its bore with the periphery of said mandrel and provided with an inwardly tapering peripheral face which is adaptv outer piston,

tudinally movable tubular Wall and a liXedl bottom arranged VWithin the inner end of said Wall, a longitudinally movable mandrel adapted to enter said Wall Jfrom the opposite end thereofyand means for ejecting the iinished forging from said die pot comprisingV a telescopic ejector rod havingV a tubular outer section and an inner section arranged Within said outer section, an outer piston connected with said outer rod section, an outer power cylinder which receives said and an inner piston connected with said inner rod section and Vmovable lengthwise in said outer tubular rod section.

6. An apparatus for making shell forgings comprising a die `pot having a longitudinally movable tubular Wall and afixed bottom arranged Within the inner end Aof I s aidfwalh a longitudinally movable mandrel adaptedto entersaid Wall from the oppo-Y site endthereo'f, and means for ejectingl the linished :forging from said-die pot compris f f ing a telescopic ejector rodfhaving a tube:V lar outer section and an inner section arranged Within ksaid outer section, an outer piston connected .With said outer rod secti on,

an oiiterrpower` cylinder which receives said section and movable lengthmeans -Y for supplying,pressure medium .to said power cylinder and tubiilarvjrod,Y and means forV limiting the .longitudinal movement of said rod sections andipiston relatively to each other "and torrsaid Vdie vpot bottom. .Y l

' FRANK'A. SHERMAN. JOSEPH MfHALIn outer piston, an inner piston connected `irvitli f ,said inner rod I Y Wise in said outer tubular -rod section,Y 

